Softex Invest Llc V-24L N710XP accident near Paradise, Montana

Probable cause

A partial loss of power during cruise flight for reasons that could not be determined because postaccident examination of the engines did not reveal evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation.

NTSB analysis

The airline transport pilot reported that, about 30 minutes after departure for the cross-country personal flight in visual conditions, he noticed a vibration. He checked the engine instruments and did not see anything abnormal. However, he noted that the airplane's airspeed and altitude were rapidly decreasing, so he applied full power to both engines, but the airplane continued to descend, indicative of a partial loss of engine power, so he chose to conduct a forced, off-airport landing in a field. The airplane impacted terrain and then came to rest after impacting a ditch.

Postaccident examinations of the airframe and engines revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The reason for the vibration and the subsequent partial loss of power could not be determined.

Text from the NTSB. Open the NTSB docket for WPR17LA046 for the full record.